Prior restraint

Prior restraint (also referred to as prior censorship or pre-publication censorship) is censorship imposed, usually by a government, on expression that prohibits particular instances of expression. It is in contrast to censorship which establishes general subject matter restrictions and reviews a particular instance of expression only after the expression has taken place.

In some countries (e.g., United States,Argentina) prior restraint by the government is forbidden, subject to certain exceptions, by a constitution.

Prior restraint can be effected in a number of ways. For example, the exhibition of works of art or a movie may require a license from a government authority (sometimes referred to a classification board or censorship board) before it can be published, and the failure or refusal to grant a license is a form of censorship as is the revoking of a license. It can also take the form of a legal injunction or government order prohibiting the publication of a specific document. Sometimes, a government or other party becomes aware of a forthcoming publication on a particular subject and seeks to prevent it: to halt ongoing publication and prevent its resumption. These injunctions are considered prior restraint because potential future publications are stopped in advance.

Not all restrictions on free speech are a breach of the prior restraint doctrine. It is widely accepted that publication of information affecting national security, particularly in wartime, may be restricted, even when there are laws that protect freedom of expression. In many cases invocation of national security is controversial, with opponents of suppression arguing that government errors and embarrassment are being covered up; examples are given below.

Publication of information on legal cases in progress may be restricted by an injunction. (Otherwise publishing of material which may affect a case is subject to penalties, but not prevented from the outset.)

In William Blackstone's Commentaries “Freedom of the Press” is defined as the right to be free from prior restraints. In addition, he held that a person should not be punished for speaking or writing the truth, with good motives and for justifiable ends. Truth alone, however, was not considered a sufficient justification, if published with bad motives.

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